This invention relates to on-site sewage or waste disposal systems where liquid waste material is absorbed by soil at the site.
At the present time, most septic sewage systems are permitted only in situations in which proper operation can be assured under all conceivable conditions. Even though a system can operate to dispose of sewage under almost all circumstances, the absence of a safety factor to permit use under all circumstances prevents the use of this type of on-site system.
The critical limitation in systems of this type is the ability of the soil to absorb liquid waste material. In areas where the percolation of the soil is poor and/or the water table is high, the soil is unable to absorb the liquid waste material flowing into the septic system. More particularly, where the water table is high, an insufficient amount of soil is available between the tile field and the water table to properly purify the waste before entry into the water table. If the soil in the drain field itself is saturated or there is a false water table around the drain field, the liquid waste material may leach to the surface.
Since the typical septic system operates on a demand basis, i.e., liquid waste material is discharged into the soil whenever the system is used and regardless of soil conditions, even periodic reductions in percolation due to saturation of the drain field or rises in the water table are intolerable since the septic system may be called upon for a discharge of liquid waste material when the water table or saturation of the soil is high. In other words, the very nature of the demand septic system requires a safety factor to assure proper operation under all conditions.
In contrast to the typical demand septic system, U.S. Pat. No. 3,844,946 -- Farrell, Jr. discloses a system wherein the liquid waste material is stored in a holding tank and periodically discharged into the soil in large slugs. According to this patent, the discharge of the liquid waste material into the soil in large slugs greatly increases the ability of the soil to absorb the liquid waste material. It is particularly important to note that the discharge of liquid waste material into the soil appears to occur regardless of the soil saturation conditions.